How to Grow Impatiens (Busy Lizzie) UK

Impatiens are the best annual flowers for shade in UK gardens. No other bedding plant matches their non-stop colour from June to October in spots where sunlight barely reaches. A north-facing border, a shaded patio container, a hanging basket under a porch — busy lizzies fill them all with flower power.

But the impatiens story changed dramatically in 2011. Downy mildew arrived and wiped out traditional busy lizzies across Britain almost overnight. Fourteen years on, the disease still persists in UK gardens. This guide covers which impatiens are safe to grow now, how to raise them from seed, and how to get the best from these shade-loving annuals. For more shade-garden ideas, see our guide to the best plants for shade.

What types of impatiens can I grow in the UK?

Three main groups of impatiens are available to UK gardeners. Each has different strengths and weaknesses.

Impatiens walleriana is the traditional busy lizzie. Plants grow 20-30cm tall with a mounding, spreading habit. Flowers are 3-4cm across in every colour except blue and true yellow. Before 2011 it was the UK’s bestselling bedding plant, with over 100 million sold annually. It remains highly susceptible to downy mildew.

New Guinea impatiens (Impatiens hawkeri) have larger flowers of 5-7cm, glossy bronze or dark green foliage, and a more upright habit reaching 30-45cm. They resist downy mildew completely. They tolerate more light than walleriana but still prefer shade from midday sun.

Balsam (Impatiens balsamina) is the old cottage garden type. Flowers sit tight against upright stems reaching 30-60cm. Less common in garden centres but easy from seed. It is unaffected by the downy mildew that targets walleriana.

New Guinea impatiens with larger blooms alongside traditional busy lizzies in containers

The downy mildew crisis explained

Downy mildew (Plasmopara obducens) reached the UK in 2011 and devastated Impatiens walleriana. The disease spread through commercial nurseries via wind-borne spores, destroying millions of plants in weeks. By 2012, most UK councils stopped planting busy lizzies in public parks. The RHS issued warnings that the pathogen persists in soil.

Symptoms appear as yellowing upper leaves with white, fluffy fungal growth on the undersides. Plants collapse within days of visible infection. Spores survive in soil and plant debris, reinfecting new plantings. There is no chemical cure available to home gardeners.

The disease is specific to Impatiens walleriana and does not affect New Guinea impatiens, balsam, or other bedding plants. It thrives in cool, humid conditions — exactly the shaded, sheltered spots where gardeners plant busy lizzies. The RHS has a detailed guide to recognising and managing the disease.

Which mildew-resistant impatiens should I grow?

The Beacon series is the standout choice for replacing traditional busy lizzies. Bred by PanAmerican Seed, Beacon impatiens are true I. walleriana varieties with genuine downy mildew resistance. They look and perform like traditional busy lizzies — mounding habit, 25-30cm tall, flowers in 10 colours. They are the closest replacement for old-fashioned busy lizzies.

SunPatiens are interspecific hybrids bred by Sakata. They combine the vigour of wild species with New Guinea impatiens. The key difference: SunPatiens tolerate full sun. They grow 30-60cm tall and flower from June until the first hard frost. They are only available as plug plants, not seed.

New Guinea impatiens remain the safest choice overall. Compact series like Divine and Harmony grow 25-35cm and suit containers. Larger series like Florific reach 40cm and fill borders quickly.

For more shade-tolerant annuals that pair well with impatiens, see our full guide.

How to grow impatiens from seed

Impatiens seed is fine, dust-like, and needs light and warmth to germinate. Start indoors from February to March — these are slow-growing seedlings that need 10-12 weeks before planting out.

Step 1: Fill modular trays with fine, peat-free seed compost. Water from below and allow to drain. The surface must be moist but not waterlogged.

Step 2: Scatter seeds thinly across the surface. Do not cover them — impatiens seeds require light for germination. Press gently with a flat board to ensure seed-to-compost contact.

Step 3: Cover trays with clear plastic lids or cling film. Place in a heated propagator at 20-24C. Germination takes 14-21 days. Remove covers as soon as seedlings emerge.

Step 4: Grow on at 16-18C in bright, indirect light. Prick out into individual 7cm pots when seedlings have two true leaves. Handle by the leaves, never the stem.

Step 5: Harden off gradually over 10-14 days in late May. Plant out after all frost risk has passed — typically early June in the Midlands.

For a detailed guide to starting seeds early, see our indoor seed sowing guide.

Impatiens seedlings at the two-true-leaf stage, ready for pricking out

How to plant impatiens in containers and hanging baskets

Containers are where impatiens truly shine. They avoid the soil-borne mildew spores that linger in garden beds and provide the perfect controlled environment.

Container choice: Use pots of 25cm diameter or larger. Hanging baskets of 35cm work well with 3-5 plants. Window boxes suit a single row at 15cm spacing. Ensure all containers have drainage holes.

Compost: Use a multipurpose peat-free compost mixed with 20% perlite for drainage. Impatiens hate waterlogged roots but also wilt rapidly if the compost dries out. The perlite balance is critical.

Spacing: Plant 15-20cm apart in containers. In hanging baskets, plant one in the centre and three around the edge for a 35cm basket. Closer spacing fills in faster but needs more frequent watering.

Feeding: Apply a balanced liquid feed (such as Vitax Q4) every 10-14 days from July onwards. Switch to a high-potash tomato feed in August to boost late-season flowers. Do not overfeed — impatiens produce more leaf than flower with excess nitrogen.

Watering: Check containers daily in summer. Impatiens wilt dramatically when dry but recover quickly once watered. Morning watering is best. Avoid wetting the foliage, especially with walleriana types, as damp leaves encourage downy mildew.

Growing impatiens in shade and north-facing borders

Impatiens are unmatched for deep shade. They flower freely in positions that receive less than 2 hours of direct sunlight daily. This makes them essential for north-facing walls, under trees, and in basement garden areas where other annuals refuse to flower.

Soil preparation: Dig in plenty of organic matter before planting. Shaded soil is often dry near walls and fences due to rain shadow. Add a 5cm mulch of composted bark after planting to retain moisture. Impatiens have shallow roots and suffer quickly in dry soil.

Planting distance: Space 20-25cm apart for ground cover. They knit together within 6 weeks to form a solid carpet of colour. Closer planting suits formal schemes; wider spacing works in mixed borders.

Colour in deep shade: White, pink, and salmon varieties show up best in low light. Deep reds and purples disappear in heavy shade. For maximum impact in dark corners, use white Beacon or pale pink New Guinea varieties.

Companion plants for shade: Combine impatiens with hostas, ferns, heuchera, and brunnera for a layered shade border. The impatiens provide flower colour from June to October while the foliage plants offer texture year-round. Our guide to annual bedding plants covers more options for mixed plantings.

Busy lizzies providing colour in a north-facing border alongside hostas and ferns

How to keep impatiens flowering all summer

Impatiens are self-cleaning and rarely need deadheading. Spent flowers drop naturally and new buds open continuously. This is a major advantage over other annuals that demand weekly deadheading.

Pinching: Pinch out the growing tips when plants reach 10cm tall. This promotes bushier growth and more flowering stems. A single pinch doubles the number of flower-bearing shoots.

Feeding: Regular feeding from mid-July extends flowering into October. A fortnightly liquid feed with a balanced NPK (such as 10-10-10) keeps plants vigorous. Switch to high-potash (tomato feed) from late August.

Watering consistency: Irregular watering causes bud drop. Impatiens shed unopened buds when stressed by drought followed by overwatering. Maintain even moisture — daily checks in containers, twice weekly in borders during dry spells.

Temperature: Growth slows below 13C and stops below 10C. Impatiens are killed by the first frost. In sheltered urban gardens, they often flower until mid-November. In exposed rural positions, expect them to finish by mid-October.

Overwintering impatiens in the UK

Impatiens are treated as annuals in the UK, but you can carry favourite plants through winter by taking cuttings.

When to take cuttings: September, before night temperatures drop below 10C. Take cuttings while plants are still vigorous and in full growth.

Method: Cut 8-10cm non-flowering shoot tips. Remove the lower two pairs of leaves. Dip the cut end in hormone rooting powder. Insert into small pots of 50:50 perlite and multipurpose compost. Water well and cover with a clear plastic bag.

Rooting: Place on a bright windowsill at 18-20C. Roots form in 2-3 weeks. Remove the plastic bag once you see new growth. An alternative method is to root cuttings in a glass of clean water — change the water every 3 days.

Winter care: Keep rooted cuttings at 15-18C on a bright windowsill. Water sparingly — the compost should be barely moist. Feed monthly with half-strength liquid feed. Avoid cold draughts and temperatures below 12C.

Spring: Pot cuttings on into 10cm pots in March. Pinch out growing tips to encourage bushy plants. Harden off in late May and plant out after the last frost.

New Guinea impatiens overwinter more reliably than walleriana types. They tolerate lower light levels indoors and are less prone to botrytis (grey mould) in humid winter conditions.

Slugs and other common problems

Slugs and snails target young plants in spring. Protect newly planted impatiens with copper tape around containers or organic slug pellets (ferric phosphate). Evening patrols with a torch are effective. Slugs are less problematic once plants are established. For broader strategies, see our organic pest control guide.

Red spider mite can attack plants in hot, dry conditions — particularly under glass or against south-facing walls. Mist foliage regularly and keep humidity high. Biological control (Phytoseiulus persimilis) is effective in greenhouses.

Vine weevil larvae eat roots in containers, causing sudden wilting. Use a biological nematode drench (Steinernema kraussei) in September. Adult weevils notch leaf edges — check for the tell-tale scalloped marks.

Botrytis (grey mould) affects overwintering plants in humid, poorly ventilated conditions. Remove dead leaves promptly, improve air circulation, and avoid overhead watering.

Downy mildew remains the biggest threat. Symptoms: yellowing leaves, white fungal fuzz on undersides, rapid collapse. Only affects I. walleriana. Remove and destroy infected plants immediately. Do not compost them.

Month-by-month impatiens calendar

Busy lizzies thriving in a hanging basket — the ideal container for these shade-loving annuals

For growing flowers alongside impatiens, see our guide on how to grow cosmos from seed — another reliable annual for UK gardens.

Frequently asked questions

Can I still grow traditional busy lizzies in the UK?

Yes, but the risk of downy mildew is high. Plasmopara obducens persists in UK soil and air since the 2011 outbreak. Traditional Impatiens walleriana varieties remain highly susceptible. If you want the classic busy lizzie look, grow Beacon series instead — they are bred from I. walleriana but carry genuine resistance to downy mildew. Avoid reusing compost from previous impatiens plantings.

Do impatiens need sun or shade?

Impatiens prefer shade to partial shade. They are the best annual for deep shade where other bedding plants fail. Traditional busy lizzies and Beacon types perform best in full shade. New Guinea impatiens tolerate more sun — up to 4 hours of morning light — but scorch in hot afternoon sun. SunPatiens are the exception and handle full sun.

When should I sow impatiens seeds in the UK?

Sow indoors from February to March at 20-24C. Seeds are tiny and need light to germinate, so press them onto the compost surface without covering. Germination takes 14-21 days. Prick out into modules when seedlings have two true leaves. Harden off in late May and plant out after the last frost in your area.

Why are my impatiens dropping their leaves?

Leaf drop is usually caused by cold stress or downy mildew. Impatiens stop growing below 10C and drop leaves below 5C. Downy mildew causes yellowing leaves with white fungal growth on the undersides, followed by rapid defoliation. Remove and destroy affected plants immediately. Downy mildew spreads through wind-borne spores and can infect an entire planting within days.

Can I overwinter impatiens?

Yes, take stem cuttings in September before temperatures drop. Cut 10cm non-flowering shoots, remove lower leaves, and root in a glass of water or moist perlite on a warm windowsill. Rooted cuttings overwinter indoors at 15-18C with good light. Plant out after the last frost the following May. This works best with New Guinea types.

What is the difference between New Guinea and standard impatiens?

New Guinea impatiens have larger flowers (5-7cm), glossy dark foliage, and tolerate more light than standard busy lizzies. They resist downy mildew. Standard I. walleriana has smaller flowers (3-4cm), lighter green leaves, and a more spreading habit. New Guinea types grow more upright to 30-45cm. Both are frost-tender annuals in the UK.

Are SunPatiens the same as impatiens?

SunPatiens are a hybrid impatiens bred by Sakata. They cross Impatiens hawkeri (New Guinea) with wild species to produce vigorous, sun-tolerant, mildew-resistant plants. They grow 30-60cm tall, handle full sun, and flower from June to November. They are sold as plug plants rather than seed. SunPatiens are the only impatiens group that thrives in full sun.